Listen from 0'34" to 1'30".
A two note melody functions as a series of common tones over 4 chords: G minor, Gb Major/Bb, Eb Major, and B Major 7. Others will hear it differently, but I hear this as an unresolved progression in the key of Bb Major. In this context, the progression starts on the relative minor (vi), followed by a bVI (borrowed from Bb minor), a IV chord, and finally ending on a flat-two chord (borrowed) from Bb Phrygian). While there are no Bb chords to be found, the melody helps to imply the key of Bb by pulsing on that note five times every bar.
Music Morsels are musical fragments, collected and analyzed.